Fluxgate magnetometers detect localized changes to the earth's magnetic field caused by presence of ferrous objects. In general, fluxgate magnetometers are of two common configurations. These two configurations are commonly referred to in the art as “core-type” and “ring-type”. In this regard, “core-type” fluxgate magnetometers include a cylindrically-shaped ferromagnetic core while “ring-type” fluxgate magnetometers include a torodial-shaped ferromagnetic core. Wrapped about the core are an excitation coil and a sensor coil. The excitation coil excites the core to produce a magnetic flux. The sensor coil senses changes in the magnetic flux due to presence of a nearby ferromagnetic object. It will be observed that the discussion hereinbelow is with respect to core-type fluxgate magnetometers. However, it should be understood by those skilled in the art that the same physical principles generally apply to ring-type fluxgate magnetometers, as well.
Although prior art fluxgate magnetometers function adequately for their intended purpose, there are problems associated with magnetic flux measurements not addressed by these prior art devices. For example, a problem overlooked by such prior art devices is that, although they will detect presence of a ferrous object, these prior art devices may not uniquely identify the object.
Another problem not addressed by such prior art devices is lack of a convenient means for enhancing resolution of the detected signal due to presence of the ferrous object.
Yet another problem apparently not addressed by prior art devices is the inability of such prior art devices to produce oscillations (necessary for magnetic signal detection) with reduced power consumption.
A further problem not addressed by prior art devices is the inability of prior art devices to suitably detect time-dependent (i.e., AC) target signals.
Therefore, what is needed is a system including oscillatory fluxgate magnetometers, and a method of assembling the system, the system capable of oscillating in response to time-dependent (i.e., A.C.) changes in an external magnetic flux generated by a target signal in order to detect the target signal with enhanced resolution and lower power consumption.